In an image forming apparatus such as a copier of an electrophotographic type, an image is formed on a recording medium (a sheet of paper and the like) by a cycle of charging, exposing, developing, and transferring. For example, a surface of a photoconductive drum is similarly charged, a laser beam is radiated to the charged photoconductive drum to form an electrostatic latent image, and the electrostatic latent image of the photoconductive drum is developed by a developing device to form a toner image.
The toner image of the photoconductive drum is primary transferred to a rotating intermediate transfer belt and the like, and the toner image is secondary transferred onto the sheet. The sheet, onto which the toner image is transferred, is heated by a fixer and a toner image is fixed on the sheet. The sheet, to which the toner image is fixed, is discharged by a transport roller.
Incidentally, in the image forming apparatus of the related art, an image can be formed on various recording media such as thick sheet, coated sheet, and thin sheet. Meanwhile, in order to be compatible with various recording media, an engine of the image forming apparatus needs to be designed so as to cope with the respective media. However, it is difficult to cope with various media from a thin sheet to a thick sheet with one engine.
Especially, in the printing on the thin sheet, a sheet may be wound around the fixer, or a sheet may be wound around a transfer belt or a transfer roller. In order to avoid the winding of the sheet, it is also considered to provide a transfer peeling portion or to provide a peeling claw in the fixer to facilitate the peeling, but there is a possibility that a claw mark is left on the sheet, which leads to an increase in costs.